P1+HRM?

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mat
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P1+HRM?

Post by mat »

Has anyone tried to combine the P1 (EL84) power section and ODS-HRM preamp together :shock: :oops: :oops: Or is it just plain impossible :(
mat
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Bob-I
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Re: P1+HRM?

Post by Bob-I »

mat wrote:Has anyone tried to combine the P1 (EL84) power section and ODS-HRM preamp together :shock: :oops: :oops: Or is it just plain impossible :(
Yes, I did quite awhile ago. It actually sounded pretty good, but nothing like a Dumble. I ended up converting that amp to an Hi-Octane and then selling it. As a Dumble clone it was ok, as a Hi-Octane it was awesome, but not my style. The new owner is very happy with it.
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RJ Guitars
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Re: P1+HRM?

Post by RJ Guitars »

Mat,

That sounds kinda interesting to me... would you share that schematic and/or layout with us?

rj
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mat
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Re: P1+HRM?

Post by mat »

Yes, I did quite awhile ago. It actually sounded pretty good, but nothing like a Dumble. I ended up converting that amp to an Hi-Octane and then selling it. As a Dumble clone it was ok, as a Hi-Octane it was awesome, but not my style. The new owner is very happy with it.
Mine is also a Hioctane with P1 switch. Not my cup of tea either.. Its laying useless on the floor.
RJ Guitars wrote:Mat,

That sounds kinda interesting to me... would you share that schematic and/or layout with us?

rj
rj, I think You meant Bob-I with this ? Bob, would it be possible to check the schem/layout - that is if You have them ?
mat
Hotrod Ford
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Re: P1+HRM?

Post by Hotrod Ford »

To make Dumble preamps work ok with el84s
you need to drop the signal going in to power tubes considerably,
a redesigned PI circuit is necesary,
stevlech
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Re: P1+HRM?

Post by stevlech »

I think one would have to play with the tail end of the preamp (mostly the OD Master volume) to get the drive right, since the P1 is a single ended circuit :wink:
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Bob-I
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Re: P1+HRM?

Post by Bob-I »

I looked around, I guess I didn't save the schematic/layout because the only one I have is the final Hi-Octane layout.

Basically I used a Hybrid preamp into the single EL-84/6V6. I had 2 power tube sockets. It did take some voltage reduction to prevent blocking distortion, I think a 470k/470k voltage divider but I'm not sure.

Overall the sound was more overdriven Champ than Dumble.
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